The central idea behind the use of a standard keyboard for language entry into computers or other devices is unchanged from that of the typewriter: words are built-up letter by letter, and if one wants to enter a particular letterxe2x80x94such as the letter xe2x80x98exe2x80x99, for examplexe2x80x94one strikes the xe2x80x98exe2x80x99 key and the letter e appears on the screen directly following the display of previous input. To build a particular word, one must use the keyboard to separately enter each letter of the word, and do so in proper sequence.
When a keyboard is used for text input of an ideographic (character-based) language such as Chinese, Japanese or Korean, a character must be called to the display screen by some keyboard input related to, or even unique to, the desired character. Keyboard entry methods for these languages range from phonetic input to number codes to sequential entry of the strokes from which characters are constructed traditionally when writing with brush, pen or pencil. So, whether the language being entered with a standard keyboard is Western or Eastern, the idea is that the user is expected to use the keyboard to xe2x80x98write.xe2x80x99 That is, if xe2x80x98writingxe2x80x99 is to be displayed on the screen, xe2x80x98writingxe2x80x99 must be done with the keyboard. With respect to ideographic languages, the use of the standard keyboard can be a real barrier. Before one can use the keyboard, one must first learn a system of inputxe2x80x94that is to say, one must learn just how the keyboard is used to tell the computer to display text on the screen. For some input methods the actual use of the keyboard is quite simple, but the user is required to learn quite a lot before even approaching the keyboard. For example, using number codes to call out the display of a particular character using a standard keyboard is easyxe2x80x94if one knows the correct code.
Any limitations imposed by language input with a standard keyboard are magnified when the same xe2x80x98writingxe2x80x99 input concept is adapted to the input systems employed with messaging wireless phones, and smaller and smaller portable computers which can not accommodate standard keyboards. In order to xe2x80x98writexe2x80x99 using something less than a full-size standard keyboard, other devices have been offered as alternatives: a telephone-style 10-number plus keypad, a screen-display touch pad with alphabetic displays, or an on-screen electronic writing pad. However, none of these approaches to direct language input without a standard keyboard is without its problems. The writing done with an electronic pad is often not well-understood by the computer. Using a telephone-style keypad means that each key is used for the input of more than one letter of the Western alphabet. In some implementations this means that the user must hit the key three or four times to get the desired letter. In other implementations the computer tries to guess the desired word, using frequency-of use data related to the keystroke input sequence.
In any of these efforts to provide a text input capability without a full-size keyboard, text entry is less intuitive, excellent spelling ability is more important, and in those cases where the computer is expected to guess the desired word based on frequency data, it will frequently be wrong, such as in the cases of xe2x80x98catxe2x80x99 and xe2x80x98actxe2x80x99, or xe2x80x98figxe2x80x99 and xe2x80x98digxe2x80x99. Moreover, in the frequently recurring case of a misspelling or typo, the user is not aware that an entry error has been made until the input is complete. Touch screens that require the grouping of letters in each xe2x80x98touch boxxe2x80x99 have similar problems to those of the telephone-style keypad, and others as well. Touch screens that attempt to use one letter per box significantly reduce the amount of display area available for other purposes (such as the space needed to display the sentence being entered), and/or reduce the display size of the letters and/or the size of their boxes, which increases input errors on small devices. Similar problems are associated with a telephone-style keypad or a touch-pad for phonetic input of character-based languages. Written entry of these languages using an electronic pad requires a great deal of computer memory and storage, and is prone to as many or more recognition problems for the computer as is experienced with Western languages.
In brief summary, the present invention provides a text input system which may be used with computers, wireless phones or other devices or systems, and which is applicable to both ideographic and non-ideographic languages. According to one aspect of the the present invention, a user inputs text through a rapid, intuitive process in which word or character candidates are presented to the user based on frequency of usexe2x80x94not of full words or whole charactersxe2x80x94but of the various sequences of letters (or strokes in Chinese-character-based languages) that are used to construct words or characters. The user need only specify the first letter or stroke of the word or character that is desired.
The sequences of letters and strokes, along with their frequency-of-use, are stored in a memory or other data storage device and may be called out as lists of increasingly complete words which are displayed to a user in frequency-of-use order. The user does not need to input particular letters or strokes, but simply choose among the increasingly more complete sequences that are offered as the word is built up by the user through the various offerings made on the display screen. The present invention operates to make frequently used words or characters quickly available at the same time that it creates efficient access to the less frequently used words or characters, and does so without the need for a full-size standard keyboard. In a preferred embodiment for devices lacking a touch screen, a standard keyboard is replaced by six keys: four arrow keys, a xe2x80x98select letter groupxe2x80x99 key, and a xe2x80x98select wordxe2x80x99 key. Where a touch screen is available for the device, no electromechanical keys will be needed; the preferred embodiment will be one in which the display screens will respond to a stylus. The invention could also be used with an electronic pen, or with voice, or with any other device that could call up and utilize the appropriate screens.